Ruler attachment.



w. A. CALDWELL.

RULBR ATTACHMENT.

APPLIOATION FILED 11017.17. 1911.

1 35,818. Patented Aug. 13, 1912.

WILLIAM A. CALDWELL, F MANILA, PHILIPPINE ISLANDS.

RULER ATTACHMENT.

Specification of Letters Patent.

Patented Aug. 13, 1912.

Application filed November 17, 1911. Serial No. 660,932.

To all whom it may concern:

Be it known that I, WVILLIAM A. Cann- WELL, citizen of the UnitedStates, residing at Manila, Province of Luzon, Philippine Islands, haveinvented certain new and useful Improvements in Ruler Attachments, ofwhich the following is a specification.

This invention relates to a ruler attachment, and has for its object. toprovide a guard slidably mounted upon a rule for movement longitudinallythereof along its forward or graduated edge.

With this object in View the invention consists in providing in theupper side of the rule a groove extending longitudinally of the scale orgraduations and providing the under side of the rule at its graduatededge with a recess which extends the length of the rule. A guard isprovided with end portions which are slidably received in the saidgroove and recess and extends around the graduations at the forward edgeof the rule and is provided at its outer forward surface with tangswhich are adapted to be engaged by the point of a pen, whereby the guardis moved longitudinally of the rule as the pen is moved along itsgraduated edge. By such an arrangement, as the pen is used for rulingstraight lines, the ink from the same cannot get upon the graduations ofthe rule or upon the body of the rule proper, but such ink as escapesfrom the pen will lodge upon the guard. This is of metal andconsequently is nonabsorbent and therefore the ink may be readily wipedfrom the guard.

For a full understanding of the invention reference is to be had to thefollowing description and accompanying drawing in which:

Figure 1 is a perspective view of a ruler with the attachment applied;Fig. 2 is a plan view of a portion of the ruler and attachment; Fig. 3is a transverse sectional view of the same; and Fig. 4 is a perspectiveview of the attachment.

Corresponding and like parts are referred to in the followingdescription and indicated in all the views of the accompanying drawingby the same reference characters.

The rule 1 to which the attachment is applied is of the usual patternand is provided upon its upper side between its forward and back edgesand behind its gradiations 2 with a longitudinally disposed groove whichextends the length of the rule and is parallel with the long edgesthereof. The groove 3 is closed at its ends by inserted blocks 4. Therule 1 is provided upon its under side and at its graduated edge with alongitudinally disposed recess 5 which extends the length of the rule.

The guard 6 is slidably mounted upon the graduated edge of the rule andis formed from a strip of thin metal having an end portion 7 which issnugly received within the groove 3. The intermediate portion of theguard 6 lies flat over the graduations of the rule and the said stripextends around the graduated edge of the rule with its other end portion8 snugly received in the said recess. The guard 6 is provided upon itsouter surface at that part which is bent around the graduated edge ofthe rule with outstanding prongs 9 which are struck up from the metal ofwhich the said guard is composed. These prongs have end portions whichare approximately at right angles to the long dimension of the rule andagainst these ends or shoulders a ruling pen may be placed when straightlines are being ruled, so that by moving the pen along the graduatededge of the rule the guard 6 will follow the pen and thus prevent anyink from passing from the pen onto the body of the rule. Any ink thatescapes from .the pen will lodge upon the guard, and as this is made ofnon-absorbent material it may be readily wiped from the same. Thereforethe rule may be freely used for guiding a pen and at the same time thereis no danger of the graduations thereof becoming obliterated or the rulesoiled. The blocks 4 in the ends of the groove 3 will prevent the guardG from slipping off of the ends of the rule and therefore for allpractical purposes the parts are permanently assembled.

Having thus described the invention, what is claimed as new is:

1. In combination with a rule having upon its upper side alongitudinally disposed groove and upon its lower side and at its edge alongitudinally disposed recess, a guard having an end portion snuglyreceived in the groove and an opposite end portion snugly received inthe recess, said guard extending around the edge of the rule.

2. In combination with a rule having upon its upper side alongitudinally disposed groove and upon its lower side and at its edge alongitudinally disposed recess; In testimony whereof I affiX mysignature blocks inserted in the ends of the groove, a in presence oftwo Witnesses.

guard havin an end portion snu ly received i n the groovz between theblocksfsaid guard ILLIAM CALDVVELL' extending around the edge of therule and Vvitnessesz having lts other end portlon snugly received ROBERTG. 000s, Within the sand recess. CLARENCE B. SHAW.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

